<template>
    <div>
        <!-- 面包屑导航区 -->
        <el-breadcrumb separator-class="el-icon-arrow-right">
            <el-breadcrumb-item :to="{ path: '/home' }">首页</el-breadcrumb-item>
            <el-breadcrumb-item>商品管理</el-breadcrumb-item>
            <el-breadcrumb-item>参数列表</el-breadcrumb-item>
        </el-breadcrumb>

        <!-- 卡片视图区域 -->
        <el-card>
            <!-- 警告区域 -->
            <el-alert
                title="注意: 只允许为第三级分类设置相关参数!"
                type="warning"
                :closable="false"
                show-icon
                center
                style="width: 28%">       
            </el-alert>
            <!-- 选择商品分类区域 -->
            <el-row class="cat_opt">
                <el-col>
                    <span>选择商品分类:</span>
                    <!-- 选择商品分类的级联选择框 -->
                    <el-cascader
                        v-model="selectedCatKeys"
                        :options="catelist"
                        :props="cateProps"
                        @change="handleChange"
                        clearable
                        >
                    </el-cascader>
                </el-col>
            </el-row>
            <!-- tab 页签区域 -->
            <el-tabs v-model="activeName" @tab-click="handleTabClick">
                <!-- 添加动态参数的面板 -->
                <el-tab-pane label="动态参数" name="many">
                     <!-- 添加参数的按钮 -->
                     <el-button type="primary" size="mini" 
                     :disabled="isBtnDisabled" @click="addDialogVisible=true">添加参数</el-button>
                     <!-- 动态参数表格 -->
                     <el-table :data="manyTableData" border stripe>
                        <!-- 索引列 -->
                        <el-table-column type="expand">
                            <template slot-scope="scope">
                                <el-tag v-for="(item, i) in scope.row.attr_vals"
                                :key="i" closable @close="handleClose(i, scope.row)">
                                    {{ item }}
                                </el-tag>
                                <!-- 输入文本框 -->
                                <el-input
                                class="input-new-tag"
                                v-if="scope.row.inputVisible"
                                v-model="scope.row.inputValue"
                                ref="saveTagInput"
                                size="small"
                                @keyup.enter.native="handleInputConfirm(scope.row)"
                                @blur="handleInputConfirm(scope.row)"
                                >
                                </el-input>
                                <!-- 添加的按钮 -->
                                <el-button v-else class="button-new-tag" size="small" 
                                @click="showInput(scope.row)">+ New Tag</el-button>                                
                            </template>
                        </el-table-column>
                        <el-table-column type="index" label="#"></el-table-column>
                        <el-table-column label="参数名称" prop="attr_name"></el-table-column>
                        <el-table-column label="操作">
                            <template slot-scope="scope">
                                <el-button type="primary" icon="el-icon-edit" size="mini"
                                @click="showEditDialog(scope.row.attrId)">编辑</el-button>
                                <el-button type="danger" icon="el-icon-delete" size="mini"
                                @click="removeParams(scope.row.attrId)">删除</el-button>
                            </template>
                        </el-table-column>
                    </el-table>
                </el-tab-pane>
                <!-- 添加静态属性的面板 -->
                <el-tab-pane label="静态属性" name="only">
                    <!-- 添加属性的按钮 -->
                    <el-button type="primary" size="mini" 
                    :disabled="isBtnDisabled" @click="addDialogVisible=true">添加属性</el-button>
                    <!-- 静态属性表格 -->
                    <el-table :data="onlyTableData" border stripe>
                       <!-- 索引列 -->
                       <el-table-column type="expand">
                            <template slot-scope="scope">
                                <!-- 循环渲染tag标签 -->
                                <el-tag v-for="(item, i) in scope.row.attr_vals"
                                :key="i" closable @close="handleClose(i, scope.row)">
                                    {{ item }}
                                </el-tag>
                                <!-- 输入文本框 -->
                                <el-input
                                class="input-new-tag"
                                v-if="scope.row.inputVisible"
                                v-model="scope.row.inputValue"
                                ref="saveTagInput"
                                size="small"
                                @keyup.enter.native="handleInputConfirm(scope.row)"
                                @blur="handleInputConfirm(scope.row)"
                                >
                                </el-input>
                                <!-- 添加的按钮 -->
                                <el-button v-else class="button-new-tag" size="small" @click="showInput(scope.row)">+ New Tag</el-button>
                            </template>
                       </el-table-column>
                       <el-table-column type="index" label="#"></el-table-column>
                       <el-table-column label="属性名称" prop="attr_name"></el-table-column>
                       <el-table-column label="操作">
                           <template slot-scope="scope">
                               <el-button type="primary" icon="el-icon-edit" size="mini"
                               @click="showEditDialog(scope.row.attrId)">编辑</el-button>
                               <el-button type="danger" icon="el-icon-delete" size="mini"
                               @click="removeParams(scope.row.attrId)">删除</el-button>
                           </template>
                       </el-table-column>
                   </el-table>
                </el-tab-pane>
            </el-tabs>
        </el-card>
        <!-- 添加参数的对话框 -->
        <el-dialog
            :title="'添加' + titleText"
            :visible.sync="addDialogVisible"
            width="50%"
            @close="addDialogClosed">
            <!-- 添加参数的表单 -->
            <el-form :model="addForm" :rules="addFormRules" ref="addFormRef" label-width="100px">
                <el-form-item :label="titleText" prop="attr_name">
                    <el-input v-model="addForm.attr_name"></el-input>
                </el-form-item>
            </el-form>
            <span slot="footer" class="dialog-footer">
                <el-button @click="addDialogVisible = false">取 消</el-button>
                <el-button type="primary" @click="addParams">确 定</el-button>
            </span>
        </el-dialog>
        <!-- 修改参数的对话框 -->
        <el-dialog
            :title="'修改' + titleText"
            :visible.sync="editDialogVisible"
            width="50%"
            @close="editDialogClosed">
            <!-- 添加参数的表单 -->
            <el-form :model="editForm" :rules="editFormRules" ref="editFormRef" label-width="100px">
                <el-form-item :label="titleText" prop="attr_name">
                    <el-input v-model="editForm.attr_name"></el-input>
                </el-form-item>
            </el-form>
            <span slot="footer" class="dialog-footer">
                <el-button @click="editDialogVisible = false">取 消</el-button>
                <el-button type="primary" @click="editParams">确 定</el-button>
            </span>
        </el-dialog>
    </div>
</template>

<script>
    export default {
        data(){
            return {
                // 商品分类列表
                catelist: [],
                // 级联选择框的配置对象
                cateProps: {
                    expandTrigger: 'hover',
                    // 具体选中值的属性
                    value: 'cat_id',
                    // 指定看到的属性
                    label: 'cat_name',
                    // 指定父子嵌套的属性
                    children: 'children',
                    // 是否严格的遵守父子节点不互相关联
                    checkStrictly: false
                },
                // 级联选择框双向绑定到的数组
                selectedCatKeys: [],
                // 被激活的页签的名称
                activeName: 'many',
                // 动态参数的数据
                manyTableData: [],
                // 静态参数的数据
                onlyTableData: [],  
                // 控制添加对话框的显示与隐藏
                addDialogVisible: false,
                // 添加参数的表单数据对象
                addForm: {
                    attr_name: ''
                },
                // 添加表单的验证规则对象
                addFormRules: {
                    attr_name: [{
                        required: true, 
                        message: '请输入参数名称', 
                        trigger: 'blur'}
                    ]
                },
                // 控制修改对话框的显示与隐藏
                editDialogVisible: false,
                // 修改的表单数据对象
                editForm: {
                    attr_name: ''
                },
                // 修改表单的验证规则对象
                editFormRules: {
                    attr_name: [{
                        required: true, 
                        message: '请输入参数名称', 
                        trigger: 'blur'}
                    ]
                }
            }
        },
        created(){
            this.getCateList();
        },
        methods: {
            // 获取所有的商品分类列表
            async getCateList(){
                const {data: res} = await this.$http.get('categories');
                if(res.meta.status !== 200){
                    return this.$message.error('获取商品分类失败!');
                }
                this.catelist = res.data;
                console.log(this.catelist);
            },
            // 级联选择框选中项变化, 会触发这个函数
            handleChange(){
                this.getParamsData();
            },
            // Tab页签点击事件的处理函数
            handleTabClick(){
                console.log(this.activeName);
                this.getParamsData();
            },
            // 获取参数的列表数据
            async getParamsData(){
                // 证明选中的不是3级分类
                if(this.selectedCatKeys.length !== 3){
                    this.selectedCatKeys = [];
                    this.manyTableData = [];
                    this.onlyTableData = [];
                    return;
                }
                // 证明选中的是三级分类
                console.log(this.selectedCatKeys);
                // 根据所选分类的Id和当前所处的面板, 获得对应的参数
                const {data: res} = await this.$http.get(
                    `categories/${this.cateId}/attributes`, 
                    {params: {sel: this.activeName}});

                if(res.meta.status !== 200){
                    this.$message.error('获取参数列表失败!');
                }
                res.data.forEach(item => {
                    // item.attr_vals !== '' ? item.attr_vals = item.attr_vals.split(' '): item.attr_vals = [];
                    item.attr_vals = item.attr_vals ? item.attr_vals.split(' ') : [];
                    // 控制文本框的显示与隐藏
                    item.inputVisible = false;
                    // 文本框中输入的值
                    item.inputValue = '';
                });
                console.log(res.data);
                if(this.activeName === 'many'){ 
                    this.manyTableData = res.data;
                }else{
                    this.onlyTableData = res.data;
                }
            },
            // 监听添加对话框的关闭事件
            addDialogClosed(){
                this.$refs.addFormRef.resetFields();
            },
            // 点击按钮添加参数
            addParams(){
                this.$refs.addFormRef.validate(async valid => {
                    if(!valid) return;

                    const {data: res} = await this.$http.post(`categories/${this.cateId}/attributes`, {
                        attr_name: this.addForm.attr_name,
                        attr_sel: this.activeName
                    });

                    if(res.meta.status !== 201){
                        return this.$message.error('添加参数失败!')
                    }

                    this.$message.success('添加参数成功!')
                    console.log(res.data);
                    this.addDialogVisible = false;
                    this.getParamsData();
                });
            },
            // 点击按钮, 展示修改对话框
            async showEditDialog(attrId){
                // 查询当前参数的信息
                const {data: res} = await this.$http.get(`categories/${this.cateId}/attributes/${attrId}`,
                {params: {attr_sel: this.activeName}});

                if(res.meta.status !== 200){
                    return this.$message.error('查询参数失败!');
                }

                this.editForm = res.data
                this.editDialogVisible = true;
            },
            // 重置修改的表单
            editDialogClosed(){
                this.$refs.editFormRef.resetFields();
            },
            // 点击按钮修改参数信息
            editParams(){
                this.$refs.editFormRef.validate(async valid => {
                    if(!valid) return;
                    const {data: res} = await this.$http.put(`categories/${this.cateId}/attributes/${this.editForm.attrId}`, {
                        attr_name: this.editForm.attr_name,
                        attr_sel: this.activeName
                    });

                    if(res.meta.status !== 200){
                        return this.$message.error('修改参数失败!');
                    }

                    this.$message.success('修改参数成功!');
                    this.getParamsData();
                    this.editDialogVisible = false;

                });
            },
            // 根据id删除对应的参数项
            async removeParams(attrId){
                const confirmResult = await this.$confirm('此操作将永久删除该参数, 是否继续?', '提示', {
                    confirmButtonText: '确定',
                    cancelButtonText: '取消',
                    type: 'warning'
                }).catch(err => err);

                // 用户取消了删除的操作
                if(confirmResult !== 'confirm'){
                    return this.$message.info('已取消了删除操作');
                }

                // 删除的业务逻辑
                const {data: res} = await this.$http.delete(`categories/${this.cateId}
                /attributes/${attrId}`);

                if(res.meta.status !== 200 ){
                    return $message.error('删除参数失败!');
                }

                this.$message.success('删除参数成功!');
                this.getParamsData();
            },
            // 文本框失去焦点, 或者按下了 enter 都会触发
            async handleInputConfirm(row){
                if(row.inputValue.trim().length === 0){
                    row.inputValue = '';
                    row.inputVisible = false;
                    return;
                }
                // 如果没有return, 则证明输入的内容需要做后续处理
                row.attr_vals.push(row.inputValue.trim());
                row.inputValue = '';
                row.inputVisible = false;

                this.saveAttrVals(row);
            },
            // 对attr_vals的操作保存到数据库
            async saveAttrVals(row){
                // 需要发起请求, 保存这次操作
                const {data: res} = await this.$http.put(`categories/${this.cateId}/attributes/${row.attrId}`, {
                    attr_name: row.attr_name,
                    attr_sel: row.attr_sel,
                    attr_vals: row.attr_vals.join(' ')
                });

                if(res.meta.status !== 200){
                    return this.$message.error('修改参数项失败!');
                }

                this.$message.success('修改参数项成功!')
            },
            // 点击按钮展示文本输入框
            showInput(row){
                row.inputVisible = true;
                // 让文本框自动获得焦点
                // $nextTick 方法的作用, 就是当页面上元素
                //被重新渲染之后, 才会执行回调函数中的代码
                this.$nextTick(_ => {
                    this.$refs.saveTagInput.$refs.input.focus();
                });                
            },
            // 删除对应的参数可选项
            handleClose(i, row){
                row.attr_vals.splice(i, 1);
                this.saveAttrVals(row);
            }
        },
        computed: {
            // 如果按钮需要被禁用, 则返回true, 否则返回false
            isBtnDisabled(){
                if(this.selectedCatKeys.length !== 3){
                    return true;
                }
                return false;
            },
            // 当前选中的三级分类Id
            cateId(){
                if(this.selectedCatKeys.length === 3){
                    return this.selectedCatKeys[2];
                }
                return null;
            },
            // 动态计算标题的文本
            titleText(){
                if(this.activeName === 'many'){
                    return '动态参数';
                }
                return '静态属性';
            }
        }
    }
</script>

<style lang="less" scoped>
    .cat_opt {
        margin: 15px 0;
    }
    .el-tag {
        margin: 10px;
    }
    .input-new-tag {
        // width: 10%;
        width: 120px;
    }
    // .button-new-tag {
    //     margin-left: 10px;
    // }
</style>